摘要
采用高速摄像机拍摄水滴撞击加热亲水管壁的动态过程,研究在不同撞击速度(韦伯数)和壁面温度下,液滴撞击后出现的液膜反弹和中心射流现象.不同于液滴撞击常温亲水管壁,液滴撞击加热亲水管壁后会反弹.在曲率比(液滴直径与管外壁直径的比值)为0.15,撞击速度为0.47~1.40 m/s,壁面温度为20~305℃的条件下,观测到“回缩-反弹”“铺展-反弹”和“破碎-反弹”3种反弹形式,总结其发生条件.壁面温度是决定液滴撞击后能否发生反弹的关键因素,壁面温度和韦伯数均对“破碎-反弹”的产生有显著影响.从重力、惯性力和气化反作用力角度分析产生快速“铺展-反弹”现象的原因.分析中心射流形成原因,发现增加壁面温度和韦伯数有利于不完全中心射流的形成.
The dynamic characteristics of water droplet impacting a hydrophilic tubular surface were recorded by a high-speed camera,the droplet rebound and central jet were studied under different impact velocities(Weber number)and surface temperatures.The droplet can rebound after impacting a heated hydrophilic tubular surface,while not for a hydrophilic tubular surface of room temperature.The curvature ratio(the ratio of droplet diameter to tube outer diameter)was 0.15,impact velocity ranged from 0.47 to 1.40 m/s,and the surface temperature ranged from 20 to 305℃,three rebound forms were observed:“retraction-rebound”“spread-rebound”and“splashrebound”,the formation conditions of which were summarized.The surface temperature determines whether droplet can rebound or not,it,as well as Weber number can influence the formation of“splash-rebound”significantly.The formation of a fast“spread-rebound”was analyzed from the gravity,inertial force,and gasification reaction force.The formation of central jet was analyzed,the increase in the surface temperature and Weber number were beneficial to the occurrence of the incomplete central jet.
作者
王开珉
张玉杰
康培森
刘宏升
刘晓华
WANG Kai-min;ZHANG Yu-jie;KANG Pei-sen;LIU Hong-sheng;LIU Xiao-hua(School of Energy and Power Engineering,Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education,Dalian University of Technology,Dalian 116024,China)
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2022年第6期1191-1198,共8页
Journal of Zhejiang University：Engineering Science
基金
辽宁省中央引导地方科技发展专项项目(2021JH6/10500150)
国家自然科学基金资助项目(51476017,51576029)。
关键词
液滴撞击
加热管壁
撞击速度
中心射流
液膜反弹
droplet impact
heated tubular surface
impact velocity
central jet
droplet rebound
